Search Publications
Frozen Martian lahars? Evaluation of morphology, degradation and geologic development in the Utopia-Elysium transition zone
Pedersen, G. B. M.
Regional coverage of high-resolution data from the CTX camera has permitted new, detailed morphologic analysis of the enigmatic Utopia-Elysium flows which dominate the transition zone between Elysium volcanic province and Utopia Planitia. Based on topographic and morphologic analysis of the Galaxias region, this study supports the lahar hypothesis…
A geological characterization of Ligeia Mare in the northern polar region of Titan
Chevrier, V. F.; Wasiak, F. C.; Androes, D. +3 more
Ligeia Mare, the second largest sea on Titan, resides in an endorheic basin dominated by seas in the northeastern polar region. Ligeia's shoreline morphology resembles terrestrial man-made reservoirs where water is dammed and valleys are flooded. Here we describe the mare and surrounding geologically diverse terrain including rugged highlands and …
Probing the flyby anomaly with the future STE-QUEST mission
Hechenblaikner, G.; Páramos, Jorge
In this study, we demonstrate that the flyby anomaly, an unexpected acceleration detected in some of the gravitational assists of the Galileo, NEAR, Cassini and Rosetta spacecraft, could be probed by accurate orbital tracking available in the proposed Space-Time Explorer and Quantum Equivalence Principle Space Test (STE-QUEST); following a recent …
A model of variability in Titan's atmospheric structure
Flasar, F. M.; Waite, J. H.; Lorenz, R. +2 more
Titan's atmosphere has been extensively studied during the Cassini-Huygens Mission. The polar environment undergoes considerable seasonal variation and is distinct from the more quiescent equatorial environment experienced by the Huygens probe in 2005. The thermal structure of the upper atmosphere is affected by interaction of Titan's atmosphere w…
The two-micron spectral characteristics of the Titanian haze derived from Cassini/VIMS solar occultation spectra
Kim, Sang Joon; Courtin, Régis; Sim, Chae Kyung +2 more
Vertically-resolved spectral characteristics of the Titanian haze in the 2-µm wavelength range were derived from solar occultation spectra measured by Cassini/VIMS on January 15, 2006. At the various altitudes probed by the solar occultation measurements, we reproduced the observed spectra using a radiative transfer program including absorpt…
Validation of methodology to derive elemental abundances from X-ray observations on Chandrayaan-1
Babu, B. R. S.; Narendranath, S.; Sreekumar, P. +2 more
The Chandrayaan-1 X-ray Spectrometer (C1XS) observed characteristic X-ray fluorescence (XRF) lines of major rock forming elements from the lunar surface during different solar flare conditions. As the Sun was undergoing an unusually low activity cycle during the observing period of C1XS (28th Nov. 2008-29th Aug. 2009), most observations were made …
The influence of slope morphology on gullies: Terrestrial gullies in Lake George as analogues for Mars
Hobbs, S. W.; Paull, D. J.; Clarke, J. D. A.
Terrestrial gullies provide a useful benchmark to compare martian gully forms against. We compare pole and equator facing gullies in an unnamed crater located in the martian southern mid-latitudes with gullies located on the Lake George escarpment south of Gearys Gap, New South Wales, Australia. Our investigations showed gully morphology at both s…
Experimental validation of XRF inversion code for Chandrayaan-1
Narendranath, S.; Sreekumar, P.; Sudhakar, M. +5 more
We have developed an algorithm (x2abundance) to derive the lunar surface chemistry from X-ray fluorescence (XRF) data for the Chandrayaan-1 X-ray Spectrometer (C1XS) experiment. The algorithm converts the observed XRF line fluxes to elemental abundances with uncertainties. We validated the algorithm in the laboratory using high Z elements (20<Z…
A model of scattered thermal radiation for Venus from 3 to 5µm
Hueso, R.; Sánchez-Lavega, A.; García Muñoz, A. +2 more
Thermal radiation becomes a prominent feature in the continuum spectrum of Venus longwards of ∼3µm. The emission is traceable to the upper cloud and haze layers in the planet's mesosphere. Venus' thermal radiation spectrum is punctuated by CO2 bands of various strengths probing into different atmospheric depths. It is thus possibl…
Dust-plasma interaction through magnetosphere-ionosphere coupling in Saturn's plasma disk
Gurnett, Donald A.; Kurth, William S.; Wahlund, Jan-Erik +4 more
The ion bulk speeds in the equatorial region of Saturn's inner magnetosphere, according to data from the Langmuir Probe (LP) on board the Cassini spacecraft, are about 60% of the ideal co-rotation speed; the ion speeds are between the co-rotation and Keplerian speeds (Holmberg et al., Ion densities and velocities in the inner plasma torus of Satur…